Changes

==Structure==

==Structure==

[[Image:Sheep Anus.jpg|thumb|right|150px|Anus (Sheep) - Copywright RVC 2008]]

[[Image:Sheep Anus.jpg|thumb|right|150px|Anus (Sheep) - © RVC 2008]]

*There are ''two'' anal sphincters:

*There are ''two'' anal sphincters:

**'''Internal anal sphincter''', formed by thickening of the circular smooth muscle of the gut and under autonomic control.

**'''Internal anal sphincter''', formed by thickening of the circular smooth muscle of the gut and under autonomic control.